Combined pump and oil tank unit, especially for servo-steering systems

ABSTRACT

A pump aggregate consisting of pressure oil pump and of an oil supply tank, particularly for servo-steering systems, which is constituted by a common housing casting with a partition wall separating the pump space from the supply space whereby the partition wall is formed integrally with the casting of the housing.

United States Patent 1 Eisen Mar. 12, 1974 COMBINED PUMP AND OIL TANK UNIT, [56] References Cited ESPECIALLY FOR SERVO-STEERING UNTED STATES PATENTS SYSTEMS 2,051,301 8/1936 Kleckner et a1, 417/310 X [75] Inventor: Peter Eisen, Stuttgart, Germany 2,536,709 H1951 Ashton et a1.

2,621,593 12/1952 Schmiel 137/565 X [73] Assigneez Daimler-Benz Aktlengesellschaft,

Stuttgart-Untertuerkheim, Germany FOREIGN PATENTS OR APPLECATIONS [22] Filed: p 13 1973 581,441 10/1946 Great Britain 417/310 Appl. No.: 351,000

Related U.S. Application Data Continuation of Ser. No. 137,775, April 27, 1971, abandoned.

Foreign Application Priority Data Apr. 28, 1970 Germany P 20 20 675.1

U.S. Cl 417/310, 137/565, 60/DIG. 10 Int. Cl.....; F041) 49/00 Field of Search 137/565, 568, 570;

Primary Examinerl-1enry T. Klinksiek Atturney, Agent, or Firm-Craig and Antonelli [57] ABSTRACT 12 Claims, 3 Drawing Figures PATENTEUHAR I 2 m4 3.796; 520

sum 1 0r 2 ATTORNE YS PATENTEDHAR 12 L974 3; 796; 520 sum 2 or 2 INVENTOR PETER EISEN BY Cml QM,

W K ALQDv ATTORNEYS COMBINED PUMP AND OIL TANK UNIT, ESPECIALLY FOR SERVO-STEERING SYSTEMS This is a continuation of my .copending application Ser. No. 137,775 filed Apr. 27, 1971 now abandoned.

The present invention relates to a pump aggregate or assembly consisting of a pressure oil pump and of an oil supply tank especially for servo-steering systems.

The present invention is concerned with the task to provide a small, light-weight and relatively inexpensive unit of the aforementioned type. The underlying problems are solved by the present invention in that a common cast housing is provided with a partition wall separating the pump space from the supply space which is constructed in one piece with the housing casting.

Separate supports for the fastening and mounting are economized by the present invention, which are necessitated if the supply tank is structurally separate from the pump housing. Compared to the last-mentioned arrangement, a structural simplification and the saving of seals are achieved by the present invention. The shape of the cast housing according to the present invention can be readily adapted to the existing installation conditions. With the housing casting of the present invention, one is far-.reachingly independent in the arrangement of the housing connections. This is not the case if one provides for the oil supply a sheet metal tank drawn about the pump housing, properly speaking.

-A space-saving arrangement is achieved according'to the present invention in that the partition wall is cylindrical and the supply space is arranged essentially concentrically about the inwardly disposed'pump space. It is advantageous in particular for technical reasons as regards casting if the cylindrical separating or partition wall is arranged eccentrically in a rectangular housing in such a manner that the partition wall has a wall sec- 1 tion in common with the housing wall.

The customary quantity-regulating valve is spacesavingly accommodated in the cast housing according to the present invention in that a housing bore for a quantity regulating valve extends in the wall section of the widened housing wall adjoining the supply space.

Further inventive features are directed to the advantageous arrangement of the'housing dome for the oil volume expansion and the fastening means of the housing casting.

Accordingly, it is an object of the present invention to provide a pump unit, especially for servo-steering systems, which avoids by simple means the aforementioned shortcomings and drawbacks encountered in the prior art.

Another object of the present invention resides in a pump unit for servo-steering systems which is of compact design, is of lightweight construction and is relatively inexpensive in manufacture and assembly.

A further object of the present invention resides in a pump aggregate of the type described above which is space-saving and permits economizing seals and the like.

These and further objects, features, and advantages of the present invention will become more apparent from the following description when taken in connection with the accompanying drawings which shows, for

FIG. 1 is an" elevational view of a pump aggregate in accordance with the present invention; I

FIG. 2 is a crosssectional view taken along line Il-Il of FIG. 1 in which only the housing casting is illustrated; and

FIG. 3 is a cross-sectional view, taken along line III- III of FIG. 2.

Referring now to the drawing wherein likereference numerals are used throughout the various views to designate like parts, reference numeral generally designates the casting of a housing which is substantially rectangular in cross-section for the illustrated rotary vane pump unit. An inner cylindrical separating or partition wall 11 is cast integral with the housing casting 10; the partition wall 11 separates the pump space 12 having a longitudinal axis 45 from the oil supply space 13 and is disposed eccentrically as shown by the spacing 48 to the center plane 14-14 (FIG. 2) of the housing casting 10. The one housing wall 15 and the partition wall 11 thereby have a wall section 16 in common.

The inner coupling pin 17 (FIG. 3) of a pump drive shaft generally designated by reference numeral 18 projects into the pump space 12', the rotor 19 carrying the vane pistons. of conventional construction and therefore not illustrated is splinedly connected with the coupling pin 17. The'vane pistons cooperate with an external stator housing 20 of conventional construction and concentric to the rotor 19, which stator housing is fixedly arranged in the pump space 12. The ring-shaped stator housing 20 is closed off at the sides by end disks I 21 and 22 provided with oil channels (not shown).

A pressure chamber 24 (FIG. 3) is separated off in the pump space 12 by the end disk21 and a housing cover 23 inserted coaxially; the pressure chamber 24 is in communication in a conventional manner not illustrated in the drawing with the two pressure spaces of the stator housing 20. The suction chamber 25 of the pump housing is disposed on the side of the end disk 21 opposite the pressure chamber 24 which is in communication with the two suction spaces in the motor housing 20 also in a conventional manner not shown in the drawing.

The housing wall 26 extending perpendicularly to the common wall section 16 has a considerably greater wall thickness S (FIG. 2) than the remaining housing walls 15, 27 and 28. The partition wall] 11 thereby passes 5 over at 29 into the widened housing wall 26. As shown,

the partition wall 11 has the shape of a circular ring segment.

Initially, housing channels 30 and 31 (FIG. 2) are provided in the widened housing wall, which connect the suction chamber 25 both with the housing connection 32 for the oil return as also with the supply space 13 and also establish a connection 33 between the housing connection 32 and the supply space 13. A

housing bore 35 with a longitudinal axis 46 for a quantity-regulating valve generally designated by reference numeral 37 (FIG. 3) andinterconnected between the pressure chamber 24 and the housing connection 36 for the pump pressure line extends in the wall section 34 which extends substantially at. right angles to the longitudinal axis 47 of the housing casting 10 and adjoins the supply space 13 of the widened housing wall 26. As shown, the longitudinal axis of the housing bore 35 is in parallel to the longitudinal axis of the pump space 12 and disposed eccentrically as indicated by the spacing 49 to the center plane 14--14 of the housing casting l and on the opposite side of the center plane from the axis 45. This valve 37 is connected with the pressure chamber 24 by a housing channel 38 also extending in the wall section 34.

The housing wall 28 (FIG. 2) carries a housing dome 39 whose interior space is in communication with the supply space 13 and is closed off against the outside by a filler pipe 40 or filler connection 40.

As can be readily seen from the drawing, the pump space 12, the supply space 13, the housing dome 39, as well as the housing bores 30, 31 and 34 are accommodated within the narrowest space. The entire unit can be secured in a simple manner by means of cast-on mounting eyes or lugs 41, 42, 43 and 44.

While I have shown and described only one embodiment in accordance with the present invention, it is understood that the same is not limited thereto, but is susceptible of numerous changes and modifications as known to those skilled in the art, and I therefore do not wish to be limited to the details shown and described herein, but intend to cover all such changes and modifications as are encompassed by the scope of the appended claims.

I claim:

1. Pump assembly comprising one of a centrififugal and rotary piston pump and an oil supply tank, especially for servo-steering systems, characterized by a common housing casting common to the pump and oil supply tank, the housing casting having a longitudinal axis and a longitudinal extending center plane, a cylindrical housing pump space having a longitudinal axis disposed substantially perpendicularly to the longitudinal axis of the housing casting, the housing casting having a partition wall means separating the pump space from a supply space for the oil, the longitudinal axis of the pump space being eccentrically disposed with respect to the longitudinal center plane of the housing casting, the partition wall means being connected by a housing wall section having an enlarged wall thickness and extending substantially perpendicularly to the longitudinal axis of the housing casting to a longitudinal housing casting wall disposed on the opposite side of the longitudinal center plane of the housing casting from that of the longitudinal axis of the housing pump space, the enlarged housing wall section being provided with a housing valve bore for a volume control valve, the housing valve bore having a longitudinal axis disposed eccentrically and on the opposite side of the longitudinal center plane of the housingcasting from that of the longitudinal axis of the housing pump space.

2. A pump assembly according to claim 1, characterized in that the casting of the housing is constructed in one piece with securing eye means.

3. A pump assembly according to claim 2, characterized in that the partition wall means has the shape of a circular ring segment in cross section.

4. A pump assembly according to claim 3, characterized in that the longitudinal axis of the housing pump space extends substantially perpendicularly to the longitudinal axis of the housing casting.

5.. A pump assembly according to claim 4, characterized in that the longitudinal axis of the housing pump space and the housing valve bore extend in parallel to one another.

6. A pump assembly according to claim 1, characterized in that the partition wall means has the shape of a circular ring segment in cross section.

7. A pump assembly according to claim 1, characterized in that the longitudinal axis of the housing pump space extends substantially perpendicularly to the longitudinal axis of the housing casting.

8. A pump assembly according to claim 1, characterized in that the longitudinal axis of the housing pump space and of the housing valve bore extend in parallel to one another.

9. A pump assembly according to claim 1, characterized in that the housing casting is a substantially rectangular housing with housing walls, the partition wall means including a common wall section together with one of the housing walls.

10. A pump assembly according to claim 9, characterized in that the housing wall disposed opposite the enlarged housing wall section carries a housing dome for the temperature-conditioned volumetric expansion of the oil.

11. A pump assembly according to claim 1, characterized in that a housing channel means is provided in the enlarged housing wall section extending between housing connection means and the pump space.

12. In a servo-steering system, a pump assembly comprising a pressure oil pump for supplying a continuous stream of oil for the servo-steering system and an oil supply tank arranged in a common housing casting, the common housing casting having a partition wall means separating a pump space for the pump from a supply space for the oil, the partition wall means having the shape of a circular ring segment in cross section and being in one piece with the casting of the housing, the supply space being arranged essentially concentrically about the inwardly disposed pump space. 

1. Pump assembly comprising one of a centrififugal and rotary piston pump and an oil supply tank, especially for servo-steering systems, characterized by a common housing casting common to the pump and oil supply tank, the housing casting having a longitudinal axis and a longitudinal extending center plane, a cylindrical housing pump space having a longitudinal axis disposed substantially perpendicularly to the longitudinal axis of the housing casting, the housing casting having a partition wall means separating the pump space from a supply space for the oil, the longitudinal axis of the pump space being eccentrically disposed with respect to the longitudinal center plane of the housing casting, the partition wall means being connected by a housing wall section having an enlarged wall thickness and extending substantially perpendicularly to the longitudinal axis of the housing casting to a longitudinal housing casting wall disposed on the opposite side of the longitudinal center plane of the housing casting from that of the longitudinal axis of the housing pump space, the enlarged housing wall section being provided with a housing valve bore for a volume control valve, the housing valve bore having a longitudinal axis disposed eccentrically and on the opposite side of the longitudinal center plane of the housing casting from that of the longitudinal axis of the housing pump space.
 2. A pump assembly according to claim 1, characterized in that the casting of the housing is constructed in one piece with securing eye means.
 3. A pump assembly according to claim 2, characterized in that the partition wall means has the shape of a circular ring segment in cross section.
 4. A pump assembly according to claim 3, characterized in that the longitudinal axis of the housing pump space extends substantially perpendicularly to the longitudinal axis of the housing casting.
 5. A pump assembly according to claim 4, characterized in that the longitudinal axis of the housing pump space and the housing valve bore extend in parallel to one another.
 6. A pump assembly according to claim 1, characterized in that the partition wall means has the shape of a circular ring segment in cross section.
 7. A pump assembly according to claim 1, characterized in that the longitudinal axis of the housing pump space extends substantially perpendicularly to the longitudinal axis of the housing casting.
 8. A pump assembly according to claim 1, characterized in that the longitudinal axis of the housing pump space and of the housing valve bore extend in parallel to one another.
 9. A pump assembly according to claim 1, characterized in that the housing casting is a substantially rectangular housing with housing walls, the partition wall means including a common wall section together with one of the housing walls.
 10. A pump assembly according to claim 9, characterized in that the housing wall disposed opposite the enlarged housing wall section carries a housing dome for the temperature-conditioned volumetric expansion of the oil.
 11. A pump assembly according to claim 1, characterized in that a housing channel means is provided in the enlarged housing wall section extending between houSing connection means and the pump space.
 12. In a servo-steering system, a pump assembly comprising a pressure oil pump for supplying a continuous stream of oil for the servo-steering system and an oil supply tank arranged in a common housing casting, the common housing casting having a partition wall means separating a pump space for the pump from a supply space for the oil, the partition wall means having the shape of a circular ring segment in cross section and being in one piece with the casting of the housing, the supply space being arranged essentially concentrically about the inwardly disposed pump space. 